Question

Надо срочно! Помогите плез

Answer 1

$1)\; \; \frac{y}{x}=4\\\\\frac{10y^2-3xy+20x^2}{8x^2+xy+y^2}=\Big [\frac{:x^2}{:x^2}\Big ]=\frac{10(\frac{y}{x})^2-3\cdot \frac{y}{x}+20}{8+\frac{y}{x}+(\frac{y}{x})^2}=\frac{10\cdot 4^2-3\cdot 4+20}{8+4+4^2}=\frac{168}{28}=6\\\\2)\; \; \frac{a}{b}=3\\\\\frac{6b^2+10ab+a^2}{a^2-ab+3b^2}=\Big [\frac{:b^2}{:b^2}\Big ]=\frac{6+10\cdot \frac{a}{b}+(\frac{a}{b})^2}{(\frac{a}{b})^2-\frac{a}{b}+3}=\frac{6+10\cdot 3+3^2}{3^2-3+3}=\frac{45}{9}=5$